Apparently Rees-Mogg has said it would be "a constitutional outrage" if the moves by Cooper et al end up with Parliament deciding it should block Brexit. To prevent this he raises the idea of proroguing Parliament if that outcome appears likely.

The whole rationale of Parliament is to agree on solution to problems like our current mess. If it looks likely to do so and then action is taken to shut it down to prevent it doing do - well, I know which looks a bigger constitutional outrage to me.